java.io.FileNotFoundException（拒绝访问）错误？但文件正在存储

I am getting an error HTTP Status 500 - java.io.FileNotFoundException: C:\sam\IMAGES (Access is denied) while saving an image in the file 'IMAGES'.I tried all the things like changing the permission of the file and tried to save it in different folder.The strange thing is that my images are actually getting stored in the file which i mentioned above.But why still its shows the error?? how to resolve this error?Tomcat is under the ownership of user.I am getting an error HTTP Status 500 - java.io